package com.agenda;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.UUID;

import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothServerSocket;
import android.bluetooth.BluetoothSocket;
import android.content.Context;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;

/**
 * This class does all the work for setting up and managing Bluetooth
 * connections with other devices. It has a thread that listens for
 * incoming connections, a thread for connecting with a device, and a
 * thread for performing data transmissions when connected.
 */
public class BluetoothService {
	//many parts of the code below were taken from samples from the official android website
	//so the original comments have also been kept.

    // Name for the SDP record when creating server socket
    private static final String NAME = "Bluetooth";

    // Unique UUID for this application
    private static final UUID MY_UUID =
        UUID.fromString("e5e67762-0c6d-4122-ac7e-785636919aa3"); //random generated

    // Member fields
    private final BluetoothAdapter mAdapter;
    private final Handler mHandler;
    private AcceptThread mAcceptThread;
    private ConnectThread mConnectThread;
    private ConnectedThread mConnectedThread;
    private int mState;
    
    // Constants that indicate the current connection state
    public static final int STATE_NONE = 0;       // we're doing nothing
    public static final int STATE_LISTEN = 1;     // now listening for incoming connections
    public static final int STATE_CONNECTING = 2; // now initiating an outgoing connection
    public static final int STATE_CONNECTED = 3;  // now connected to a remote device

    //Contact data
    public String name;
    public String phoneNumber;
    /**
     * Constructor. Prepares a new Bluetooth session.
     * @param context  The UI Activity Context
     * @param handler  A Handler to send messages back to the UI Activity
     */
    public BluetoothService(Context context, Handler handler, String name,String phoneNumber) {
        mAdapter = BluetoothAdapter.getDefaultAdapter();
        mState = STATE_NONE;
        mHandler = handler;
        
        //important! if BluetoothService is called by the phone that is SHARING, then the parameters
        //name and phoneNumber will contain the contact data that is being shared
        //however, if it is called by the phone that is RECEIVING, name and phoneNumber will both be null
        this.name = name;
        this.phoneNumber=phoneNumber;
    }

    /**
     * Set the current state of the chat connection
     * @param state  An integer defining the current connection state
     */
    private synchronized void setState(int state) {
        mState = state;

        // Give the new state to the Handler so the UI Activity can update
        mHandler.obtainMessage(P3_AgendaExchangeActivity.MESSAGE_STATE_CHANGE, state, -1).sendToTarget();
    }

    /**
     * Return the current connection state. */
    public synchronized int getState() {
        return mState;
    }

    /**
     * Start the chat service. Specifically start AcceptThread to begin a
     * session in listening (server) mode. Called by the Activity onResume() */
    public synchronized void start() {

        // Cancel any thread attempting to make a connection
        if (mConnectThread != null) {mConnectThread.cancel(); mConnectThread = null;}

        // Cancel any thread currently running a connection
        if (mConnectedThread != null) {mConnectedThread.cancel(); mConnectedThread = null;}

        setState(STATE_LISTEN);

        // Start the thread to listen on a BluetoothServerSocket
        if (mAcceptThread == null) {
            mAcceptThread = new AcceptThread();
            mAcceptThread.start();
        }
    }

    /**
     * Start the ConnectThread to initiate a connection to a remote device.
     * @param device  The BluetoothDevice to connect
     * @param secure Socket Security type - Secure (true) , Insecure (false)
     */
    public synchronized void connect(BluetoothDevice device) {
        // Cancel any thread attempting to make a connection    	
        if (mState == STATE_CONNECTING) {
            if (mConnectThread != null) {mConnectThread.cancel(); mConnectThread = null;}
        }

        // Cancel any thread currently running a connection
        if (mConnectedThread != null) {mConnectedThread.cancel(); mConnectedThread = null;}

        // Start the thread to connect with the given device
        mConnectThread = new ConnectThread(device);
        mConnectThread.start();
        setState(STATE_CONNECTING); 
    }

    /**
     * Start the ConnectedThread to begin managing a Bluetooth connection
     * @param socket  The BluetoothSocket on which the connection was made
     * @param device  The BluetoothDevice that has been connected
     */
    public synchronized void connected(BluetoothSocket socket, BluetoothDevice
            device, final String socketType) {

        // Cancel the thread that completed the connection
        if (mConnectThread != null) {mConnectThread.cancel(); mConnectThread = null;}

        // Cancel any thread currently running a connection
        if (mConnectedThread != null) {mConnectedThread.cancel(); mConnectedThread = null;}

        // Cancel the accept thread because we only want to connect to one device
        if (mAcceptThread != null) {
            mAcceptThread.cancel();
            mAcceptThread = null;
        }

        // Start the thread to manage the connection and perform transmissions
        mConnectedThread = new ConnectedThread(socket, socketType);
        mConnectedThread.start();
        
        setState(STATE_CONNECTED);
    }

    /**
     * Stop all threads
     */
    public synchronized void stop() {
    	
        if (mConnectThread != null) {
            mConnectThread.cancel();
            mConnectThread = null;
        }

        if (mConnectedThread != null) {
            mConnectedThread.cancel();
            mConnectedThread = null;
        }

        if (mAcceptThread != null) {
            mAcceptThread.cancel();
            mAcceptThread = null;
        }
        setState(STATE_NONE);
    }

    /**
     * Write to the ConnectedThread in an unsynchronized manner
     * @param out The bytes to write
     * @see ConnectedThread#write(byte[])
     */
    public void write(byte[] out) {
        // Create temporary object
        ConnectedThread r;
        // Synchronize a copy of the ConnectedThread
        synchronized (this) {
            if (mState != STATE_CONNECTED) return;
            r = mConnectedThread;
        }
        // Perform the write unsynchronized
        r.write(out);
    }

    /**
     * Indicate that the connection attempt failed and notify the UI Activity.
     */
    private void connectionFailed() {
        // Send a failure message back to the Activity
        Message msg = mHandler.obtainMessage(P3_AgendaExchangeActivity.MESSAGE_TOAST);
        Bundle bundle = new Bundle();
        bundle.putString(P3_AgendaExchangeActivity.TOAST, "Unable to connect device");
        msg.setData(bundle);
        mHandler.sendMessage(msg);
    }

    /**
     * Indicate that the connection was lost and notify the UI Activity.
     */
    private void connectionLost() {
        // Send a failure message back to the Activity
        Message msg = mHandler.obtainMessage(P3_AgendaExchangeActivity.MESSAGE_TOAST);
        Bundle bundle = new Bundle();
        bundle.putString(P3_AgendaExchangeActivity.TOAST, "Bluetooth disconnected.");
        msg.setData(bundle);
        mHandler.sendMessage(msg);
    }

    /**
     * This thread runs while listening for incoming connections. It behaves
     * like a server-side client. It runs until a connection is accepted
     * (or until cancelled).
     */
    //the phone that is sharing will keep running this thread, waiting
    //for the phone that is receiving to connect
    private class AcceptThread extends Thread {
        // The local server socket
        private final BluetoothServerSocket mmServerSocket;
        private String mSocketType;

        public AcceptThread() {
            BluetoothServerSocket tmp = null;

            // Create a new listening server socket
            try {
            	//first assign it to a temporary server socket, because mmServerSocket is final.
                tmp = mAdapter.listenUsingRfcommWithServiceRecord(NAME, MY_UUID);
            } catch (IOException e) {
            }
            mmServerSocket = tmp;
        }

        public void run() {
            BluetoothSocket socket = null;

            // Listen to the server socket if we're not connected
            while (mState != STATE_CONNECTED) {
                try {
                    // This is a blocking call and will only return on a
                    // successful connection or an exception
                    socket = mmServerSocket.accept();
                } catch (IOException e) {
                    break;
                }

                // If a connection was accepted
                if (socket != null) {
                    synchronized (BluetoothService.this) {
                        switch (mState) {
                        case STATE_LISTEN:
                        case STATE_CONNECTING:
                            // Situation normal. Start the connected thread.
                            connected(socket, socket.getRemoteDevice(),
                                    mSocketType);
                            break;
                        case STATE_NONE:
                        case STATE_CONNECTED:
                            // Either not ready or already connected. Terminate new socket.
                            try {
                                socket.close();
                            } catch (IOException e) {
                                //Log.e(TAG, "Could not close unwanted socket", e);
                            }
                            break;
                        }
                    }
                }
            }
            //if (D) Log.i(TAG, "END mAcceptThread, socket Type: " + mSocketType);

        }

        public void cancel() {
            try {
                mmServerSocket.close();
            } catch (IOException e) {
                //Log.e(TAG, "Socket Type" + mSocketType + "close() of server failed", e);
            }
        }
    }


    /**
     * This thread runs while attempting to make an outgoing connection
     * with a device. It runs straight through; the connection either
     * succeeds or fails.
     */
    //this thread is run by the phone that is receiving
    //the phone that is receiving has the MAC address of the other phone (read from the QR)
    private class ConnectThread extends Thread {
        private final BluetoothSocket mmSocket;
        private final BluetoothDevice mmDevice;
        private String mSocketType;
        
        public ConnectThread(BluetoothDevice device) {
            mmDevice = device;
            BluetoothSocket tmp = null;
            
            // Get a BluetoothSocket for a connection with the
            // given BluetoothDevice
            try {
                tmp = device.createRfcommSocketToServiceRecord(MY_UUID);
            } catch (IOException e) {
                //Log.e(TAG, "Socket Type: " + mSocketType + "create() failed", e);
            }
            mmSocket = tmp;
        }

        public void run() {
            //Log.i(TAG, "BEGIN mConnectThread SocketType:" + mSocketType);

            // Always cancel discovery because it will slow down a connection
            mAdapter.cancelDiscovery();

            // Make a connection to the BluetoothSocket
            try {
                // This is a blocking call and will only return on a
                // successful connection or an exception
                mmSocket.connect();
            } catch (IOException e) {
                // Close the socket
                try {
                    mmSocket.close();
                } catch (IOException e2) {
                   // Log.e(TAG, "unable to close() " + mSocketType +
                     //       " socket during connection failure", e2);
                }
                connectionFailed();
                return;
            }

            // Reset the ConnectThread because we're done
            synchronized (BluetoothService.this) {
                mConnectThread = null;
            }

            // Start the connected thread
            connected(mmSocket, mmDevice, mSocketType);
        }

        public void cancel() {
            try {
                mmSocket.close();
            } catch (IOException e) {
                //Log.e(TAG, "close() of connect " + mSocketType + " socket failed", e);
            }
        }
    }

    /**
     * This thread runs during a connection with a remote device.
     * It handles all incoming and outgoing transmissions.
     */
    private class ConnectedThread extends Thread {
        private final BluetoothSocket mmSocket;
        private final InputStream mmInStream;
        private final OutputStream mmOutStream;

        public ConnectedThread(BluetoothSocket socket, String socketType) {
            mmSocket = socket;
            InputStream tmpIn = null;
            OutputStream tmpOut = null;
            
            // Get the BluetoothSocket input and output streams
            try {
                tmpIn = socket.getInputStream();
                tmpOut = socket.getOutputStream();
            } catch (IOException e) {
                //Log.e(TAG, "temp sockets not created", e);
            }

            mmInStream = tmpIn;
            mmOutStream = tmpOut;
        }

        public void run() {
           // Log.i(TAG, "BEGIN mConnectedThread");
            byte[] buffer = new byte[1024];
            int bytes;
           //Check if the name is null or not. 
            if(name != null) //this means, if this service is being run by the phone that is sharing
        	{     
            	//Combine name and phoneNumber to form a complter string
        	    String nameAndPhone=name.concat("#").concat(phoneNumber);
        	    //Convert nameAndPhoneNumber to bytes array to make it ready to send using bluetooth
        		byte[] send = nameAndPhone.getBytes();
                write(send);        		
            }         
                         
            // Keep listening to the InputStream while connected
            while (true) {
                try {
                	{
                	// Read from the InputStream                                	
                    bytes = mmInStream.read(buffer); //this is done in both cases, if phone is receiving or if it's sharing
                    								 //because then we can catch the exception and know when the connection is lost
                    								 //however, if phone is sharing, it won't do anything with this variable (see next line of code)
                    
                    // Send the obtained bytes to the UI Activity
                    if(name == null) //this means, if this service is being run by the phone that is receiving
                    	mHandler.obtainMessage(P3_AgendaExchangeActivity.MESSAGE_READ,bytes, -1, buffer)
                            .sendToTarget();                    
                	}
                } catch (IOException e) {
                    //Log.e(TAG, "disconnected", e);
                    connectionLost(); 
                    break;
                }
                
            }
        }

        /**
         * Write to the connected OutStream.
         * @param buffer  The bytes to write
        */
        public void write(byte[] buffer) {
            try {
          	    mmOutStream.write(buffer);
          	    
                // Tell the UI Activity we've written.
                mHandler.obtainMessage(P3_AgendaExchangeActivity.MESSAGE_WRITE, -1, -1, buffer)
                      .sendToTarget();
            } catch (IOException e) {
               // Log.e(TAG, "Exception during write", e);
            }
        } 

        public void cancel() {
            try {
                mmSocket.close();
            } catch (IOException e) {
                //Log.e(TAG, "close() of connect socket failed", e);
            }
        }
    }
}
